Laparotomy sponges

ABSTRACT

A laparotomy sponge is formed from a multiplicity of plies of open-meshed bleached absorbent gauze of a cover factor of not greater than 3.5, wherein the yarns of each ply are kinked, convoluted, and twisted into interengagement with the adjacent plies of gauze. The plies are thereby held together in relatively non-displaceable relationship, and the sponge has increased loft and elasticity.

1111mm States Patent 1191 1111 3,837,344 Patienc Sept. 24, 1974 [54]LAPAROTOMY SPONGES 3,683,921 8/1972 Brooks et a1 128/296 [75] Inventor:Donald Patience, Barrington In. 3,698,393 10/1972 Stone 128/296 [73]Assignee: The Kendall Company, Walpole, Primary Examiner-Richard A.Gaudet MBSS- Assistant Examiner-Henry J. Recla [22] Filed: Oct. 20, 1972I ggilrirltleyjrAgent, or Firm-John F. Ryan; Edward J. 21 Appl. No.:299,366

[57] ABSTRACT [52] [1.5. (:1. A laparotomy p g i formed from a h p y ofI111. Cl. p i of open meshed bleached absorbent gauze of a [58] Fleld ofSearch 128/284 296 cover factor of not greater than 3.5, wherein theyarns of each ply are kinked, convoluted, and twisted into [56]References C'ted interengagement with the adjacent plies of gauze. TheUNITED STA S PATENTS plies are thereby held together in relatively non-2,081,370 5/1937 Secrist 128/296 displaceable relationship, and thesponge has in- 3,190,289 6/1965 Patience 128/296 creased loft andelasticity. 3,491,802 1/1970 Mortensen et al.... 128/296 3,542,02711/1970 Higgins 128/284 3 Claims, 4 Drawlng Flgures mail; 344

RAIEnnnsarzmam PRIOR ART PRIOR ART FIG. 3

LAP OTOMY SPONGES by a more economical process than conventional packs.

BACKGROUND OF THE INVENTION This invention is concerned with surgicallaparotomy sponges commonly referred to as ABD packs, or abdominalpacks. ABD packs are often used in surgical procedures involving theopening of the abdominal wall by surgical incision whereby body organsand delicate membranes and tissues are exposed. These delicate bodymembers when exposed to the air are subject to radically differentenvironmental conditions than are normally encountered in the moistwarmth of the body. It is considered good surgical procedure, therefore,to simulate an environment more nearly approaching the naturalenvironment by using ABD packs moistened with warm saline solution. Suchmoistened packs are inserted into the cavity to protect and isolatethose interior body organs and tissues not directly involved fromaccidental impact and environmental hazards of the immediate operativearea. In the operative area itself ABD packs, either dry or onlyslightly moistened, are used to sponge and soak up any surplus bodyfluid present.

ABD packs have evolved over many years of surgical practice. Presentlyused ABD packs are an attempt to retain both the advantages of thin,flexible single layers and the absorptive cushioning and insulatingproperties of thicker padlike structures. As a result, the ABD pack hastraditionally been formed of multiple layers of low-' count gauzelikematerial which are unified by a sewing operation along fairly widelyseparated lines extending longitudinally or transversely, or in the caseof packs of appreciable size, in both directions. Unification hasuniversally been accomplished by lines of machine stitching whether thepack is formed of separated layers or, as is more common, by folding asingle width of fabric. Such unification of the multiple layers of thepack has been necessary to minimize the possibility of the separateplies of gauze shifting in position with respect to each other, with theformation of undesirable and possibly trauma-inducing folds andwrinkles, either during use or during laundering and reclaiming.Although hitherto regarded as essential, such crossstitching is asubstantial element in the cost of producing conventional abdominalpacks.

Packs of this sort, made from bleached absorbent gauze, have arelatively harsh hand, and are not considered suitable for applicationto delicate body organs without pretreatment. Therefore, it is an almostuniversal hospital practice to launder such packs before their initialuse, to soften the pack and render it less traumatic. This launderingprocedure introduces pills of fiber onto the surface of the pack, whichnecessitates a combing operation for pill removal to avoid the danger offibrous pills or lint becoming detached from the pack, being left in thebody, and giving rise to a foreign body reaction. The processing ofconventional packs before their initial use, therefore, is a tedious andexpensive process, complicated by the necessity of individually wrappingand sterilizing the packs prior to their introduction into the operatingroom. Packs made in accordance with this invention may be prepackaged aswrapped, single and sterilized units, ready for use.

It is with improvements in the manufacture of abdominal packs made fromwoven gauze that the present invention is concerned.

It is an object of the present invention to provide an improved processfor the manufacture of abdominal packs.

It is a further object of the invention to provide a woven abdominalpack of enhanced bulk and softness, comparable in hand with a washedgauze pack, and not requiring laundering before use.

An additional object of the invention is to provide a woven abdominalpack comprising a plurality of layers of open-meshed gauze in which theindividual layers of gauze are interengaged in relativelynon-displaceable relation to each other without the use ofcross-stitching to hold the layers together.

Other objects of the invention will be apparent from the followingdescription and drawings, in which:

FIG. 1 is a front elevation of a conventional woven gauze prior artabdominal pack.

FIG. 2 is a similar elevation of the pack of the present invention.

FIG. 3 is a cross-section of the prior art pack of FIG. 1 along the lineA-A.

FIG. 4 is a cross-sectional view of the pack of FIG. 2 along the lineB-B.

DESCRIPTION THE INVENTION In carrying out the process of this invention,a multiplicity of layers of bleached, absorbent, low-count gauze areplied together, and while in plied and superimposed condition aresubjected to strong agitation in a water bath, preferably hot, and theplied assembly is then slack dried, without any substantial warpwise orfillingwise tension. By the agitation process, both the warp yarns andthe filling yarns are kinked, bent, and convoluted into athree-dimensional spatial configuration, as distinctfrom the planarconfiguration of the individual layers of untreated gauze, and theassembly shrinks at leastlO percent in warp and filling. Theconvolutions and kinks induced into the yarns of one gauze layer arethus caused to penetrate into the meshes of the adjacent gauze layer orlayers, so that the finished slack-dried multilayered assembly behavesas a thick, soft, unitary piece of fabric, strongly resistant toattempts to delaminate or separate one treated gauze layer from another.

In selecting a suitable gauze fabric for the process of thisinvention,care must be exercised to provide a proper size of intersticesbetween yarns to allow the kinking and convoluting yarns to be convertedinto a three-dimensional configuration in which they penetrate, inrandom and irregular fashion, into the interstices of the adjacent layerof gauze, becoming enmeshed and interlocked therewith. One measure ofthe space available to a yarn to depart, under stress, from its normallinear path is expressed by the so-called cover factor of the fabric,which indicates the ratio of space in a fabric occupied by yarns to thespace occupied by the spaces between the yarns. Cover factor may thus beregarded as a measure of the degree of openness of a fabric i.e., anindication of the portion of a fabric area occupied by solid yarnsversus the portion occupied by open spaces between the yarns.

Mathematically, cover factor is the count or number of yarns in an inchof fabric layer divided by the square root of the size of the yarns inthat layer, size being expressed in the cotton system (number of hanksof yarn, 840 yards long, in a pound of yarn).

Since the warp (end) count and the filling (pick) count usually aredifferent, and since different size warp and filling yarns are usuallyemployed in a fabric, the warp and filling cover factors in any wovenfabric structure are usually different. An arithmetical average of thewarp and filling cover factors is an index of the openness of a fabric.

As representative of a class of tightly woven fabrics, a common wovenduck fabric has a 52 X 49 count, with l8s 2-ply yarns in warp andfilling. The warp cover factor is 17: the filling cover factor 16.Fabrics with an average cover factor of 13 or higher are regarded astight or closely-woven fabrics.

Diaper fabrics are in an intermediate class, with cover factors ofaround 7, 8, or 9. Neither diaper fabrics nor closely-woven fabrics aresuitable for use as abdominal packs, due to their relativeimpenetrability and to the fact that when wet such fabrics tend tobecome relatively firm, and do not conform to the contours of bodycavities and body organs.

It has been found that novel, inexpensive, and functional addominalpacks can be constructed according to this invention by employing pliesof open-mesh fabric wherein the average of the warp and filling coverfactors is not greater than about 3.5. Such packs are soft andconformable and are capable of delivering adequate amounts of warmsaline solution and of absorbing into their inner structure the viscousbody fluids when they are used for sponging purposes.

As suitable fabrics for use in this invention, bleached absorbent gauzeis selected which comprises yarns from 20's to 60's yarn size, with the30s to 40s range being preferred, and with a thread count of 8 X 8 toabout 18 X 12, with 14 X 8 or 14 X 10 being preferred.

A preferred process for stabilizing a multi-ply openmeshed array ofbleached absorbent gauze may be derived from the process set forth inSecrist US. Pat. No. 2,081,370, which describes a hot water bulkingtreatment of single-layer open-meshed fabrics. In the process of thepresent invention, a multi-ply array of bleached absorbent gauze, such a6 superimposed layers of 14 X 8 gauze, is fed to a hot water bath whereit is subjected to agitation to shrink and bulk up the assembly, afterwhich the multi-ply assembly is removed from the bath and dried withouttension.

The single-layered fabric of US. Pat. No. 2,081,370 is characterized bythe presence in the fabric ofa multiplicity ofcrunodal loops, whereyarns curve up or down out of the plane of the fabric, form a completeloop, and then continue their path in their original direction. Suchloops are substantially lacking in the product of this invention,presumably due to inter-ply interference with complete yarn freedom torearrange itself. Instead, the yarns in each ply of fabric are throwninto a series of bends, kinks, and convolutions rising out of the fabricplane and entangling and enmeshing with the perturbations in the yarnstructures of the adjacent layer of fabric. The result is a unitary,coherent multilayered fabric which can be manipulated, sewn, andgenerally handled by conventional processing without the need of sewingor otherwise securing the layers together.

Referring to the drawings, FIG. 1 represents a conventional prior artabdominal pack 10 of open-meshed gauze, four superimposed gauze layers,12, 14, 16, and 18, being shown. Unless special provision is made, theindividual layers of gauze have a tendency to slide on each other andform objectionable folds and wrinkles, especially when laundered. Acommon method of counteracting this slippage tendency is to provide thepack with sets of cross-stitching 22 and 13, spaced 3 or 4 inches apart,so that the layers of the pack are secured in a set of squares orrectangles. As mentioned above, such a sewing operation is an expensivepart of the process of producing abdominal packs.

FIG. 3 is a cross-sectional view of the cut edge of the pack of FIG. 1along the line AA. The filling yarns 24 and warp yarns 25 are arrangedin a plain weave, but each layer of fabric stands individually apartfrom each other layer, and the plies of fabric, unless otherwisesecured, can be separated from each other by a slight lifting effort.

FIG. 2 is a front elevation of a typical abdominal pack 30 of thisinvention, wherein the warp and filling yarns 32 are seen to follow atortuous and cursive path. This is seen more clearly in FIG. 4, which isa crosssectional view of the pack of FIG. 2 along the line B-B. It ischaracteristic of the packs of this invention that the various layers ofthe pack are held together in relatively non-displaceable relationshipby the interpenetration of the yarns of one layer into the intersticesbetween the yarns of the adjacent layer or layers. Therefore, in FIG. 4,no attempt is made to distinguish between warp yarns and filling yarns,since it is practically impossible in examining such a cross-section totell the original orientation of any single yarn, or even to which layerin the fabric it belongs, without careful microscopic dissection.

In forming the packs of this invention, a suitable number of plies ofbleached absorbent gauze, such as the six plies of 14 X 8 gauzementioned above, are made to enmesh and cohere strongly to each other bythe above-described process. This is done in continu ous fashion, sothat the result is a roll of soft and lofty multi-ply gauze which can becut and sewn as a unitary fabric. From this, in conventional manner butavoiding tension as far as practical, the proper size of pack is cut:typical pack sizes are 12 X 12 inches, 8 X 36, and 18 X 8.

As an index of the degree of inter-ply adhesion in the packs of thisinvention, a six-layered pack was prepared from 14 X 10 gauze, with 30swarp and 40s filling, with the layers intermeshed as set forth above. A6-inch long strip of six-ply gauze, 2 inches wide, was cut from thepack. One inch was removed from the top three layers of gauze at oneend, and from the bottom three layers at the other end. The strip wassuspended vertically with the upper edge clamped. A force of over 40grams had to be applied to the lower edge of the strip to separate theplies of the strip in the 4-inch overlap zone. When this was repeatedwith a conventional pack, either the plies fell apart merely on beingsuspended, or a force of only three or four grams would cause the pliesof the strip to separate.

Pieces of yarn separate readily from the cut edges of open mesh lowcount fabrics, and their presence of course is very undesirable in asponge or pack intended for use inside a body cavity. Pieces of yarn arenot digested or assimilated by body fluids, but instead the human systemtreats such yarns as foreign bodies, and attempts to encapsulate them,leading to pain and irritation, or more severe symptoms, in the patient.It has been the universal practice, therefore, to fold in the raw cutedges of a multi-layered abdominal pack, and to overstitch the folded-inedges securely, to prevent raveling, or to secure the thread ends in thecut edges by the application of a soft polymeric sealant. Such edgesecurement, 20in FIG. 1 and 34 in FIG. 2, is conventional.

It is also common practice in many varities of abdominal pack to providea radiopaque telltale, sewn into or affixed to the pack, and a loop oftape attached to one corner of the pack. This loop is left projectingfrom the body cavity during surgery, to provide a ready check on thecount of packs in use. Either or both of these refinements may beincorporated into the packs of this invention, and being conventionalthey are not shown.

OTHER EMBODIMENTS An especially economical pack may be produced inaccordance with this invention if a three-layered gauze construction,of, say, 14 X 8 or 14 X 10 count, is woven as a unit. For convenience inhandling and subsequent processing, the three layers may be tiedtogether at intervals by interweaving the yarns of one layer with theother layers, as set forth in US. Patent Application Ser. No. 250,238,filed May 4, 1972. The three-layered structure is boiled and bleached inconventional manner, and then, in the bleached absorbent state, issubjected to the process of US. Pat. No. 2,081,370, which softens thegauze and causes the plies to interengage with each other as set forthabove.

The gauze is then folded laterally on itself, forming a six-layeredassembly which is cut to length, and which needs to be sewn only alongthree edges, since the fold edge does not require protectiveedge-stitching to guard against the escape of cut threads.

In addition to being more economical to manufacture than packs whichrely on cross-stitching to secure the plies together, the packs of thisinvention have properties of loft, softness, and elasticity which makethem especially acceptable to the surgeon. A pack comprising six layersof untreated bleached absorbent 14 X 8 gauze had a thickness of 0.030inches, measured on an Ames gauge Type 382 with a foot 1.5 inches indiameter. A similar six ply fabric processed according to this inventionyielded a pack that measured 0.070 inches in thickness. When thenecessary corrections for gauze shrinkage are made, it is found that theapparent density (grams per unit of volume) of the lofty packs of thisinvention is approximately half of the density of conventional packs. Inthe example immediately above, the apparent density of the conventionalpack was 0.124 grams per cubic centimeter, and of the pack processedaccording to this invention, 0.066 grams. It is preferred that packsproduced in accordance with this invention have an apparent density, asmeasured above, of not more than 0.08 grams per cubic centimeter.

Additionally, the bulking operation carried out on the multi-ply gauzeassembly results in a lengthwise and widthwise contraction of 10 percentto 20 percent or so, which is reflected in the elasticity andconformability of the final pack. This elasticity, together withenhanced loft, imparts to the pack a soft resilience which is notafforded by conventional adbominal packs hitherto available. It ispreferred that packs produced according to this invention becharacterized by a ready elongation of at least 10 percent in both warpand filling, with substantially immediate and complete recoverytherefrom.

Having thus described my invention, I claim:

1. A soft, elastic, bulky, absorbent laparotomy sponge which comprises amultiplicity of superimposed plies of open-meshed gauze,

the individual warp and filling yarns of each ply of gauze being kinked,twisted and convoluted out of the normal two-dimensional plane of gauzefabrics,

the kinks and convolutions of the yarns in each individual ply of gauzebeing enmeshed with and embedded into the kinks and convolutions of theyarns in each adjacent ply of gauze,

the multiple plies of gauze thus being secured in relativelynon-displacable relation to each other as a unitary, coherent fabrichaving an apparent density of not over 0.08 grams per cubic centimeter,and said plies having means sealing said fabric against thread end loss.

2. The product according to claim 1 in which the sponge has a readyelongation of at least 10 percent in both warp and filling, withsubstantially complete and immediate recovery therefrom.

3. The process of producing a soft, elastic, bulky absorbent laparotomysponge which compries:

plying together a multiplicity of layers of openmeshed bleachedabsorbent gauze, said openmeshed gauze having an average cover factornot greater than 3.5;

subjecting the thus-formed plied array of gauze to violent agitation ina water bath;

inducing kinks, bends and convolutions in the individual warp andfilling yarns of each layer of gauze. thereby causing theinterpenetration of the yarns of one layer into the interstices betweenthe yarns of the adjacent layer or layers so as to produce a unitary,coherent fabric;

removing said unitary, coherent fabric from said water bath and dryingsaid fabric without tension;

cutting said fabric into the shape of a laparotomy sponge;

and sealing the cut edges of said fabric against thread end loss.

1. A soft, elastic, bulky, absorbent laparotomy sponge which comprises amultiplicity of superimposed plies of open-meshed gauze, the individualwarp and filling yarns of each ply of gauze being kinked, twisted andconvoluted out of the normal twodimensional plane of gauze fabrics, thekinks and convolutions of the yarns in each individual ply of gauzebeing enmeshed with and embedded into the kinks and convolutions of theyarns in each adjacent ply of gauze, the multiple plies of gauze thusbeing secured in relatively non-displacable relation to each other as aunitary, coherent fabric having an apparent density of not over 0.08grams per cubic centimeter, and said plies having means sealing saidfabric against thread end loss.
 2. The product according to claim 1 inwhich the sponge has a ready elongation of at least 10 percent in bothwarp and filling, with substantially complete and immediate recoverytherefrom.
 3. The process of producing a soft, elastic, bulky absorbentlaparotomy sponge which compries: plying together a multiplicity oflayers of open-meshed bleached absorbent gauze, said open-meshed gauzehaving an average cover factor not greater than 3.5; subjecting thethUs-formed plied array of gauze to violent agitation in a water bath;inducing kinks, bends and convolutions in the individual warp andfilling yarns of each layer of gauze, thereby causing theinterpenetration of the yarns of one layer into the interstices betweenthe yarns of the adjacent layer or layers so as to produce a unitary,coherent fabric; removing said unitary, coherent fabric from said waterbath and drying said fabric without tension; cutting said fabric intothe shape of a laparotomy sponge; and sealing the cut edges of saidfabric against thread end loss.